Search the FAQ Archives

3 - A - B - C - D - E - F - G - H - I - J - K - L - M
N - O - P - Q - R - S - T - U - V - W - X - Y - Z
faqs.org - Internet FAQ Archives

ZyXEL modem FAQ List v4.2, Nov 20 1995, Part 3 of 5 [Technical FAQs]
Section - T.20A How does the voice quality compare versus the Rockwell chipset?

( Part1 - Part2 - Part3 - Part4 - Part5 - Single Page )
[ Usenet FAQs | Web FAQs | Documents | RFC Index | Property taxes ]


Top Document: ZyXEL modem FAQ List v4.2, Nov 20 1995, Part 3 of 5 [Technical FAQs]
Previous Document: T.20 How good is the voice quality?
Next Document: T.20B When will better quality speech at higher encoding rates be available?
See reader questions & answers on this topic! - Help others by sharing your knowledge
--------------------------------------------------------------------------------

Kolja Waschk (kawk@Yo.COM) writes:
"Rockwell chipsets do higher quality voice replay. This may be due to the fact
that they use a slightly more complicated ADPCM enconding or due to the fact,
that - in addition to ZyXEL modems - Rockwell chipsets are capable of
encoding the signal using 4 bits per sample. However, the RW chipsets do the 
sampling at 7200 Hz, the ZyXELs do it at 9600 Hz; that make me believe that 
the quality difference depends mostly on the coding algorithm (and tables) 
used.  On ZyXEL modems, it's nearly impossible to record voice without any 
digitally generated background noise; on those Rockwell equipped modems 
which I have seen (heard), it IS possible."


User Contributions:

Comment about this article, ask questions, or add new information about this topic:

CAPTCHA




Top Document: ZyXEL modem FAQ List v4.2, Nov 20 1995, Part 3 of 5 [Technical FAQs]
Previous Document: T.20 How good is the voice quality?
Next Document: T.20B When will better quality speech at higher encoding rates be available?

Part1 - Part2 - Part3 - Part4 - Part5 - Single Page

[ Usenet FAQs | Web FAQs | Documents | RFC Index ]

Send corrections/additions to the FAQ Maintainer:
rwong@direct.ca (Robert Wong Jr.)





Last Update March 27 2014 @ 02:11 PM